Apparatus for actuating the pressure rollers of sawing machines



y 18, 1939- K. E. EVRELL 2 7 APPARATUS FOR ACTUATING THE PRESSURE ROLLERS OF SAWING MACHINES Filed April 1, 1937 4 SheetsSheet 1 v jam/751';

Kaleb {KEY/7'6 0 July 18, 1939. K. E. EVRELL 2,156,627

APPARATUS FOR ACTUATING THE PRESSURE ROLLERS OF SAWING MACHINES Filed April .1, 1937 4 Sheets-Shget 2 July 18, 1939. K. E. EVRELL 2,166,627

APPARATUS FOR ACTUATING THE PRESSURE ROLLERS OF SAWING MACHINES Filed April 1, 1937 4 Sheets-Sheet 3 M651: 1%,; fi'vrelz;

July 18, 1939. EfEvR-ELL 2,166,627

APPARATUS FOR ACTUATING THE PRESSURE ROLLERS 0F SAWING MACHINES Filed April 1, 1937 4 Sheets-Sheet 4 1 5 I 33g/JWK 2 319.9. /azw'wza,

Patented July 18, 1939 UNITED STATES PATENT OFFICE APPARATUS FOR ACTUATING THE PRES- SURE ROLLERS OF SAWING MACHINES Application April 1, 1937, Serial No. 134,416 In Sweden April 9, 1936 13 Claims.

Sawing machines are generally provided with two pairs of fluted rollers for feeding the logs toward and through the saw frame, each pair consisting of a lower or feed roller mounted in stationary bearings and an upper or pressure roller adjustable in vertical direction so as to suit different dimensions of the logs to be sawn. The upper or pressure rollers are further mounted in such a manner that they can freely move, to a certain extent, in a vertical direction for the purpose of adjusting themselves in accordance with minor variations in the dimension of a log. In sawing logs to be fed from the top ends the pressure rollers adjust themselves. If, on the contrary, logs are to be sawn that have great variations in dimension or are fed from the root end, it is desirable to be able easily to lift the pressure rollers prior to feeding the logs. It has previously been proposed to carry out the lifting of the pressure rollers by means of an auxiliary force.

The primary object of my invention is to improve the controlling device for the back pressure rollers so that the person attending the feeding of the logs need not survey this roller which he cannot see from his place in front of the sawing machine and on which account he meets difficulties in adjusting the roller in proper time, which may also be easily neglected by him.

Another object of my invention consists in arranging the controlling device in such a manner as to automatically put the auxiliary force in and out of action for lifting the back pressure roller and to put the same into operation by lowering the front pressure roller.

In a preferred embodiment I provide separate lifting devices for the front and back pressure rollers operated by the auxiliary force, in which case the lifting device for the front roller is operated and controlled manually, whereas the lifting device for the back pressure roller is operated in such a dependent relation to the front roller that the auxiliary force will actuate the back pressure roller first after it has ceased to influence the front roller, the control of the back roller being thereupon effected automatically and dependently of the driving means of the sawing machine.

For a better understanding of the nature of the invention and the manner in which it is carried into effect, reference may be had to the accompanying drawings forming a part of this specification and the following description thereof.

In the drawings:

Fig. 6 isa section taken on line VIVI of 5 Fig. 4;

Fig. '7 is a section taken on line VII-V II of. Fig. 4; and

Fig. 8 is a section taken on line VIIIVIII of Fig. 6.

Fig. 9 is a side elevation of Fig. 8 viewed from the left, showing the arms 29 and 30 in their normal positions.

Fig. is a view similar to Fig. 9, showing the arms 29 and 39 in the same position as these arms are disclosed in Fig. 8.

Referring to Figs. 1 and 2, numerals and denote the front and back pressure roller respectively. By means of links 4, these rollers are suspended on cross pieces 3 and 3 respectively. In the drawings, like parts of the two roller lifting devices are indicated by the same numerals, the numerals relating to the back rollers being provided With apostrophes.

The lower or feed rollers indicated at 58 and 50 respectively are mounted in bearings 5|, 5?: in the frame 53 of the sawing machine. Mounted on the main drive-shaft 54 is a sprocket wheel I9 which by means of the chain 55 drives a sprocket wheel 56 secured on a shaft 51 carrying a pinion 58. This pinion meshes with two gear wheels 59 and 59 mounted on the shafts of the rollers 50 and 50 respectively. Also the pressure rollers and I are driven from the chain 55 by means of sprocket wheels 6B and 60', gears 6|, 62 and 6|, B2, and sprocket wheels 63, 64 and 63', 64 respectively.

Each of the cross-pieces 3, 3' is carried by a piston rod of a piston 2 (Fig. 3) arranged in a pressure cylinder 5. Pressure medium is supplied to the pressure cylinders via a control valve 1 through conduits 8 and 8, telescopic pipes 9 and 9 and stationary conduits l0 and I0 respectively. In order to soften the shocks caused by the rollers, buffer springs and |2 are arranged in the pressure cylinders.

In order to reduce the velocity of fall, if the supply of pressure medium to the space under the piston 2 is interrupted and pressure medium withdrawn, a non-return valve I3 having a throttled by-pass I4 is disposed between the control valve I and the pressure cylinders 5. If the rollers are being lifted, unrestricted flow to the pressure cylinders is rendered possible, whereas during the lowering of the rollers the pressure medium is caused to pass through the throttled by-pass conduit I4.

The supply and discharge conduits for the pressure medium are indicated at I5 and I6 respectively. The controlling device connected with the control valve 1 is enclosed by a casing I 'I. The controlling device receives its movements synchronously with the feeding movement by means of a shaft I8 driven by a worm gear 20 the driving wheel of which is mounted on the shaft 54. The controlling device is manually operable by means of three different cords or the like. The cord 2I connected to the lever 22 is normally used for lifting the front pressure roller I and for starting the device for the automatic lifting of the back pressure roller I. By means of the cords 23 and 24 actuating a double-armed lever 25, lifting of either of the pressure rollers is obtained independently of the automatic device and without the same being brought into operation.

As will be seen from Fig. 4, the control valve 1 is in the form of a slide valve having a slide 26 which conducts the pressure medium supplied through pipe I5 either to the discharge I6 or to either of the pipes 8 or 8 connected to the pressure cylinders. In the intermediate position of the slide valve 26 shown in Fig. 4, pressure medium can freely flow from the supply I5 to the discharge I6. The pipes 8 and 8 are also in communication with the discharge pipe and are thus released from medium under pressure, and both pressure rollers I and I are then in their lower positions. If the slide valve 26 is moved to the left (Fig. 4) the connection between the supply I5 and the discharge I8 is interrupted and the pressure medium is conducted solely to the pipe 8 connected to the pressure cylinder of the front pressure roller I, and this roller will thus be lifted. In this case, the conduit 8' communicates, by means of a central bore 26a and lateral openings 261) provided in the slide valve, with the discharge pipe I 6. If the slide valve 26 is moved to its right hand end position the conduit 8 will be connected with the discharge pipe I6 and the roller I will be lowered, whereas pressure medium is conducted from the conduit I5 through the conduit 8 to the pressure cylinder of the back pressure roller which will thus be lifted.

The controlling device for shifting the slide valve 26 is arranged as follows. The slide valve is provided with an elongation 260 into which extends a pin 21 secured to an arm 29. The arm 29 is rigidly mounted on a shaft 28 loosely journalled in the casing II. The double-armed lever 25 is secured to the upper end of the shaft 28. Around the shaft 28 is loosely mounted a sleeve 28a rigidly connected with the lever 22. At the lower end of the sleeve 28a is secured an arm 30 on which is rotatably mounted a roller 3|. On the outer end of the arm 30 is loosely mounted a pawl 32.

In a downwardly projecting portion 38a of the arm 30 is threaded a bolt 33 which extends through an opening 29a in the arm 29. Between a nut 33a secured to the free end of the bolt 33 and the arm 29 is arranged a helical spring 33b which moves the arm 29 if the arm 30 is turned but permits movement of the arm 29 even if the arm 36 is prevented from movement. The mode of operation of the spring 331) is illustrated in Fig. 8 showing the parts in a position in which the arm 29 is swung inwardly towards the shaft I8, although the arm 30 is prevented from following this movement by means of the roller 3| which abuts against a cam 34. Since the double-armed lever 25 is secured to the shaft 28 and the arm 29 and thus also the slide valve 25 may move freely, it is always possible to adjust the said slide valve by pulling either of the cords 23 or 24 connected to the lever 25. By pulling the cord 23 the front pressure roller will be lifted, and by pulling the cord 24 the back pressure roller will be lifted.

Secured to the pawl 32 is the one end of a helical spring 35 the other end of which is connected to the casing II. This spring tends to hold the roller 3I against the cam 34 and at the same time presses a projection 32a of the pawl 32 against a ratchet wheel 36 provided with but one recess 31.

The arm 29 is normally located substantially below the arm 39. If the double-armed lever 25 is not actuated and the cord 2I of the lever 22 is pulled, the arms 29 and 30 will be turned so that the roller 3| will move away from the cam 34 (Fig. 8). The slide valve 26 is thereby moved to the left, as viewed in Fig. 4, and the pressure medium will be conducted in such a way as to lift the front pressure roller. At the same time the projection 32a engages the recess 31 of the ratchet wheel 36.

While a pull is exerted on the cord 2|, the end of a log is placed between the rollers I and 50, whereupon the cord is released. The spring 35 then moves the arms 29 and 30 and the slide valve 26 back into their intermediate positions, and the conduit 8 will be connected to the dis charge pipe I6 with the result that the front pressure roller I will be lowered onto the log. By means of the pawl 32, the spring 35 simultaneously imparts movement to the ratchet wheel 36, this movement being used, as described hereinafter, for the engagement of the cam 34 with the shaft I8 in such a manner, that the cam will rotate one revolution and thereupon automatically be released. If the cam has turned through an angle at (Fig. 8) the roller 3I slides inwardly against the shaft I8 and the slide valve 26 is thereby moved to the right as viewed in Fig. 4. Pressure medium will then be supplied to the lifting cylinder of the back pressure roller I and this roller will be lifted. If the cam is turned through a further angle [3 the roller 3I will slide outwardly to the projecting portion of the cam. Thereby the arm 30 and the slide valve 26 are moved to their intermediate positions so that the conduit 8' will be brought into communication with the discharge pipe I6, and the back pressure roller I will be lowered. Since the movement of the cam and the feeding movement of the sawing machine are synchronous, the lifting and lowering movements of the roller I will occur automatically and, if suitable angles a and c are chosen, always at the proper moment and independently of the velocity of feed.

In the embodiment shown the cam 34 and the ratchet wheel 36 are made in one piece and keyed on a hollow shaft 38 which is rotatably mounted around the shaft [8. Rigidly connected with the hollow shaft 38 is a casing 39. In this casing is arranged a piston 42 provided with a tooth 4i and movable against the action of a spring 40 (Fig. 6). On a portion 43 screwed to the piston is provided a tooth 45 preferably movable against the action of a spring 44 and located opposite the tooth 4!. The tooth 4| normally engages a recess provided on the lower surface of a ring member 46 secured to the easing ll. The tooth 45 is intended to cooperate with a toothed wheel 41 keyed on the shaft I8 but is normally out of engagement with said wheel.

If the cord 2! is released, the spring 35 turns, by means of the pawl 32 engaging the recess 33, the ratchet wheel 3% and thus also the hollow shaft 38 and the casing 39 to such an extent,-

that the tooth M will be disengaged from the ring member 45. The tooth G5 is thereby brought into engagement with the toothed wheel ll with the result that the shafts i8 and 38 will be rigidly connected with each other. After the shaft 38 and the cam 34 have turned one revolution the tooth 48 comes again into engagement with the recess of the ring member 46, and the tooth 45 and the hollow shaft 38 will be released.

As will be seen, the embodiment described above is operating semi-automatically, for the reason that no substantial difficulties are encountered by the person operating the feeding of the logs manually to start the lifting of the front roller, whereas it is of the greatest importance that he need not take care of the control of the back pressure roller. The fundamental idea that lowering or lifting and lowering of the back pressure roller is controlled by means of a device which is driven synchronously with the feeding means of the sawing machine may, however, also be applied to purely automatically operated machines of the type referred to.

While in the example shown a pneumatic or hydraulic pressure is used for the production of the auxiliary force, it is to be understood that the invention is not limited thereto. Lifting and lowering of the rollers may also take place electrically or purely mechanically without departing from the scope of the invention.

What I claim is:

1. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a. drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, said cam being in the form of a hollow shaft loosely mounted on said connecting shaft, means for imparting movement from said cam to said valve device, locking means mounted on said cam shaft, and a notched member mounted on said connecting shaft, said locking means being adapted upon displacement in one direction to engage said notched member.

2. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusts in vertical direction by means of. an auxiliary force, driving means comprising a ire for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shalt, a cam on said shaft, a

connecting shaft for imparting movement from said drive shaft to said cam shaft, said cam shaft being in the form of a hollow shaft loosely mounted on said connecting shaft, means for imparting movement from said cam to said valve device, locking means mounted on said cam shaft, a notched member mounted on said con.- necting shaft, a stationary member having a recess, said locking means having a first projection adapted to engage said notched member and a second projection disposed oppositely to said first projection and adapted to engage said resees in said stationary member, and resilient means for forcing said locking means out of engagement with said notched member and toward said stationary member.

' 3. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, a lever actuated by said cam and connected to said valve device, means for manually adjusting said lever independently of said cam, locking means mounted on said cam shaft, a notched member mounted on said connecting shaft, a stationary member having a recess, said locking means having a first projection adapted to engage said notched member and a second projection disposed oppositely to said first projection and having a cam surface adapted to engage said recess in said stationary member, resilient means for forcing said locking means out of engagement with said notched member and toward said stationary member, a springaotuated pawl mounted on said lever, and a ratchet wheel having one recess mounted on said cam shaft, said pawl being adapted to turn said ratchet wheel and said cam shaft to such an extent that said second projection is forced out of engagement with said stationary member and that said first projection is forced into engagement with said notched member whereby to connect said cam shaft with said connecting shaft.

4. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, driving means for said feed rollers, means for lifting and lowering said front pressure roller, a movable controller operatively connected to said lifting and lowering means and adapted upon being moved into a first position to cause lifting of said front pressure roller and, upon being moved into a second position to cause lowering of said front pressure roller, means for lifting and lowering said back pressure roller, and means operatively connected to the lifting and lowering means of the back pressure roller responsive to the movement of said controller from said first position to said second position for automatically moving said controller into a third position, whereby to cause lifting of said back pressure roller.

5. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, driving means for said feed roll-- ers, means for lifting and lowering said front pressure roller, a controller adapted upon being moved into a first position to cause lifting of said front pressure roller and, upon being moved into a second position to cause lowering of said front pressure roller, means for lifting and lowering said back pressure roller, means responsive to the movement of said controller from said first position to said second position for automatically moving said controller into a third position, whereby to cause lifting of said back pressure roller, and for moving said controller back into said second position after a predetermined period of time, whereby to cause lowering of said back pressure roller.

6. In a sawing machine having feed rollers and a least one front pressure roller and one back pressure roller, driving means for said feed rollers, means for adjusting said front pressure roller in vertical direction, controlling means for adjusting said back pressure roller in vertical direction by means of an auxiliary force, a first cylinder having a pressure-actuated piston for lifting said front pressure roller, a second cylinder having a pressure-actuated piston for lifting said back pressure roller, pressure medium supply and discharge conduits connected to said cylinders, and a valve device operable manually for controlling said supply and discharge conduits of both of said cylinders.

7. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a controller for actuating said valve device, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, means for imparting movement from said cam to said valve device, means responsive to the movement of said controller for connecting said cam shaft with said connecting shaft, and means adapted to disconnect said last-named shafts after a predetermined period of time from the connection of said shafts.

8. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out i of action, a controller for actuating said valve device, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, a lever actuated by said cam and connected to said valve device, a resilient member adapted to press said lever against said cam, means for manually adjusting said lever independently of said cam, means responsive to the movement of said controller for connecting said cam shaft with said connecting shaft, and means adapted to disconnect said last-named shafts after a predetermined period of time from the connection of said shafts.

9. In a sawing machine having feed rollers and at least one front pressure roller and one X back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, a lever actuated by said cam and connected to said valve device, a resilient member adapted to press said lever against said cam, means for manually adjusting said lever independently of said cam, means for connecting said cam shaft and said connecting shaft, means for disconnecting said last-named shafts after a predetermined period of time from the connecting of the shafts, a pressure medium supply conduit and a pressure medium discharge conduit connected to said valve device, a first cylinder having a pressure-actuated piston for lifting said front pressure roller, a second cylinder having a pressure-actuated piston for lifting said back pressure roller, a first connecting pipe between said valve device and said first cylinder, and a second connecting pipe between said valve device and said second cylinder, said valve device, said lever and said cam being arranged relative to each other in such a manner that in the intermediate position of said last-named parts said supply conduit as well as said connecting pipes are in communication with said discharge conduit, and that, if the valve device has been manually controlled by means of said lever, said supply pipe is in communication with said first cylinder whereby to lift said front pressure roller, and that, after the manual control of said valve device is finished and said cam commences to turn, said cam adjusts said valve device at first in such a manner that said supply pipe is in communication with said second cylinder whereby to lift said back pressure roller, and thereupon moves said valve device back into the intermediate position.

10. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a controller for actuating said valve device, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, said cam shaft being in the form of a hollow shaft loosely mounted on said connecting shaft, means for imparting movement from said cam to said valve device, means responsive to the movement of said controller for connecting said cam shaft with said connecting shaft, and means adapted to disconnect said last-named shafts after a predetermined period of time from the connection of said shafts.

11. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a controller for actuating said valve device, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, a lever actuated by said cam and consisting of a first arm connected to said valve device and a second arm ooacting with said cam, resilient means acting on said arms and adapted to permit of movement of said first arm independently of said second arm, means responsive to the movement of said controller for connecting said cam shaft with said connecting shaft, and means adapted to disconnect said last-named shafts after a predetermined period of time from the connection of said shafts.

12. In a sawing machine having feed rollers and at least one front pressure roller and one Ill) back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, a lever actuated by said cam and consisting of a first arm connected to said valve device and a second arm coacting with said cam, resilient means acting on said arms and adapted to permit of movement of said first arm independently of said second arm, and means for connecting said cam shaft and said connecting shaft during one revolution of said connecting shaft.

13. In a sawing machine having feed rollers and at least one front pressure roller and one back pressure roller, said pressure rollers being adapted to be adjusted in vertical direction by means of an auxiliary force, driving means comprising a drive shaft for said feed rollers, a valve device for putting said auxiliary force in and out of action, a cam shaft, a cam on said shaft, a connecting shaft for imparting movement from said drive shaft to said cam shaft, means for imparting movement from said cam to said valve device, means for connecting said cam shaft and. said connecting shaft, means for disconnecting said last-named shafts after one revolution of said connecting shaft, a pressure medium supply conduit and a pressure medium discharge conduit connected to said valve device, a first cylinder having a pressure-actuated piston for lifting said front pressure roller, a second cylinder having a pressure-actuated piston for lifting said back pressure roller, a first connecting pipe between said valve device and said first cylinder, a second connecting pipe between said valve device and said second cylinder, non-return valves in each of said connecting pipes permitting flow of pressure medium toward said cylinders only, and throttled conduits lay-passing said non-return valves.

KALEB EMIL EVRELL. 

